Study highlights difficulty of measuring non-clinical factors that could influence FDA drug approval decisions
While there have been growing concerns in recent years about whether the US Food and Drug Administration (FDA) decision-making might be influenced by external factors, a recent scoping paper suggests that measuring such influence is a complex task.
FDA has been subject to concerns that controversial approval decisions may be the result of political pressure, institutional constraints, and commercial interests, among other factors. However, measuring any potential influence using empirical evidence can be challenging, Robin Forrest, of the department of health policy at The London School of Economics, and colleagues wrote in their study, which was recently published in Health Affairs Scholar.
“A multidisciplinary synthesis is needed to identify common approaches, clarify where empirical findings converge or diverge, and highlight priorities for future research to understand better factors that may influence FDA drug approval decisions,” they said.
Forrest and colleagues identified 15 empirical studies published between 1990 and 2025 evaluating factors other than clinical evidence that the authors linked to FDA decision-making, including nine studies from political science and public administration, five from health policy, and one from the strategic management literature. The researchers grouped explanatory variables in FDA decision-making into categories assessing sponsor characteristics, internal FDA organizational and structural factors, decision-making procedures, changes in the regulatory landscape, and external political pressures.
A majority of the included studies (66.6%) analyzed the speed of FDA drug approval as a proxy for decision quality. While the implementation of the Prescription Drug User Fee Act (PDUFA) and an increase in staffing sped up review times, it also led to a “clustering” of decisions around regulatory deadlines, raising questions about approval timing and quality. Authors of the included studies disagreed on whether other factors, such as a firm's characteristics and reputation, affected drug approval decisions.
The most consistent factor associated with FDA approval quality was whether the agency closely aligned with its advisory committee recommendations. “Advisory committee recommendations strongly correlated with FDA decisions, although the agency occasionally diverged, usually when it adopted a more cautious stance,” Forrest and colleagues said. “Authors suggested that advisory committees may help reduce uncertainty and offer greater legitimacy or political cover, particularly for controversial decisions.”
Diverging from advisory committee recommendations “can carry significant consequences,” the researchers said, and a decline in the use of advisory committees for new drugs “may reflect strategic limitation of independent scrutiny rather than passive disengagement, raising questions about whether the FDA selectively deploys advisory committees to manage reputational risk.”
FDA also appears to be susceptible to external political and stakeholder pressure, with several included papers noting that factors such as media attention, disease salience, and advocacy group wealth led to faster approval times. One author suggested that FDA “makes decisions not only to follow science or law but to maintain legitimacy among multiple audiences: Congress, industry, media, and the public.”
However, the researchers emphasized that the evidence base for their findings was limited. “The relatively small empirical literature we identified in this scoping review, with mixed findings across the 5 factors examined, likely reflects the inherent difficulty of measuring informal influence empirically, rather than the absence of influence,” Forrest and colleagues said.
The researchers suggested that using approval speed as a primary outcome for assessing decision quality may not be the best measure for evaluating patient outcomes. They noted that more data are needed on the potential influence of these factors, as well as how approvals based on more limited evidence impact patients.
“Future research would benefit from moving beyond approval speed as a primary outcome toward more patient-centered measures, such as whether approved drugs deliver meaningful clinical benefit, to understand better how factors beyond clinical evidence shape the quality of FDA drug approval decisions,” they concluded.
